Abstract Background: Thrombocytopenia is a significant risk for patients with chronic HCV infection and a common side-effect of treatment with pegylated (PEG) interferon (IFN). Thrombocytopenia predisposes patients to bleeding and requirements for platelet transfusions, and may thus place an increased burden on patients and on medical resource utilisation.

Scope: In a retrospective analysis of an integrated, longitudinal database of medical and pharmacy claims and laboratory results in a US commercial health (insurance) plan, patients with chronic hepatitis C viral (HCV) infection were identified by reviewing ICD-9-CM HCV-, chronic liver disease-, and cirrhosis-related diagnoses. Medical resource utilisation and laboratory results were evaluated during the year following the HCV diagnosis index date as well as during the baseline year prior to that index date. Medical resource utilisation was determined by comparing outpatient visits, emergency department (ER) visits, and inpatient hospital stays for HCV patients with or without thrombocytopenia.